In recent years, utilization of a wireless power transmission technology has been considered as battery charging means such as batteries of mobile phones. In such a wireless power transmitter apparatus, there is such a known technology that a resonance coil of the power transmitter apparatus is opposed to that of a power reception apparatus, thereby electric power is transmitted. As this kind of wireless power transmitter apparatus, it is known by, for example, Patent Literature 1.
According to Patent Literature 1, the power reception apparatus performs a matching adjustment to achieve impedance matching of a receiving antenna with a rectification portion for the matching portion of the power reception apparatus in such a state that the transmission power is lower than a defined power value W1a, and thereafter, the power reception apparatus receives the transmission power of the defined power value W1a. The power reception apparatus has an adjustment load, which is connected to a prescribed position on the subsequent stage side of the matching portion of the power reception apparatus in place of the battery at the time of matching adjustment to make the impedance when the battery side is viewed from the prescribed position coincide with the impedance when the battery side is viewed from the prescribed position while the rectification portion is supplying a direct-current voltage Vo to the battery in the power receiving state of the reception power of the defined power value W1a, and therefore, it is possible to prevent from decreasing the transmission efficiency.